JP2002103441A - Method for producing bend resin pipe and apparatus for molding bent pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automate a process for producing a bent pipe of a thermoplastic resin and to mold the bent resin pipe in a good bending shape. SOLUTION: The bent resin pipe is produced through a process in which a straight raw material pipe 10A of the thermoplastic resin is prepared, a process in which the pipe 10A is moved in the longitudinal direction, and a scheduled part to be bent is pressed along the peripheral part of a bending roller 22 arranged in the front to be bent forcibly, a process in which hot air is sprayed in both directions of the inside and outside of the bent part toward the bent part while being bent forcibly, and the bent part is softened/deformed plastically and bent/molded in a shape along the peripheral part of the roller 22, and a process in which the bent/molded part is cooled by a spraying cold air to the part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a bent resin pipe and a bending equipment used for the method.

[0002]

2. Description of the Related Art Curved pipes made of a thermoplastic resin have been used for various purposes. For example, a resin bent pipe of this kind is used in combination with a metal pipe as a fuel transport pipe of an automobile. This is because a relative movement due to vibration occurs between the engine, the fuel tank, and various devices arranged in the communication path between the engine and the fuel tank, and this is absorbed by a flexible resin bent pipe. .

FIG. 15 shows an example. This example shows an example of a fuel transport pipe for transporting and supplying fuel in a fuel tank of an automobile to an engine side. In the case of the fuel transport pipe 200, most of the fuel transport pipe 200 is configured by a metal pipe 206. While this is fixed to the vehicle body, a part thereof is constituted by a flexible resin bent pipe 202, and the resin bent pipe 2 is provided.
02 is connected to the metal tube 206 on the vehicle body side, and the other end is connected to the metal tube 21 on the engine 204 side or the fuel tank 208 side.
0, and relay and communicate with each other via the resin bent tube 202. The bent resin tube 202 is merely an example, and various other forms are conventionally used for various purposes.

Conventionally, as shown in FIG. 16, this kind of bent resin pipe 202 is a straight tubular raw material pipe 202 made of a thermoplastic resin.
A is prepared by extrusion molding or the like, and is fitted into an overall constraining mold 214 having a U-shaped cross section to restrict its shape. Then, the whole of them is placed in a heating furnace 216, for example, at 150 to 160 ° C and 20 to 30 ° C. After heating for about one minute to give a bent shape, these were taken out of the heating furnace 216 and cooled,
As shown in FIG.
It was manufactured by the procedure of removing it from 4.

[0005]

However, in the case of this manufacturing method, a heating furnace 216 is required as equipment, and the heating furnace 216 occupies a large installation space. In this case, there is a problem that a large amount of heat energy is consumed.

In the case of this manufacturing method, the bent resin pipe 20
In addition to the necessity of a dedicated overall constraining mold 214 for each different product shape, size, type, etc., in the case where it is necessary to manufacture a large number of products of the same type (generally, this is the case), Requires a large number of overall constraint types 214, and a large number of overall constraint types 2
14 is required. In addition, this manufacturing method has a problem that it is difficult to produce a large variety of products in a small amount, and it is difficult to carry out mixed production in which different products are simultaneously produced on the same line.

Furthermore, in the case of this manufacturing method, the whole constraining mold 214 itself has a considerable heat capacity (the whole constraining mold 214 is made of, for example, aluminum) and is heated to a predetermined temperature in the heating furnace 216. Since it is necessary to raise the temperature, it takes a long time to heat the heating furnace 216, and it takes a long time to remove them from the heating furnace 216 and cool them. This is a factor that hinders a reduction in the manufacturing time of the 202. Also, when manufacturing a long resin bent tube of 3 to 4 m, a large overall restraint type 21 is required.
4 and a large heating furnace are required, and the equipment cost is also high.

Further, the work of fitting and setting the straight tubular material tube 202A into the whole constraining mold 214 and the work of taking out the resin bent tube 202 from the whole constraining mold 214 after the heat treatment are performed.
In addition to the problem of the number of processes and the amount of work required to obtain the resin bent tube 202 as a product, the manual bending operation is required because the manual operation is required. There was a problem that automation was difficult and the production efficiency was low.

As a result, in the case of this manufacturing method, the production cost of the bent resin pipe becomes high. In addition, in the case of this manufacturing method, in particular, when the curvature of the bent portion of the resin bent tube is small, that is, when the bending R is small, a kink (buckling or bending) occurs at the bent portion, or as shown in FIG. As described above, the cross-sectional shape of the bent portion is likely to be flat, and this causes a problem that the product is defective or the quality is reduced.

Another essential drawback of this manufacturing method is that, as shown in FIG.
However, there is a problem that the connecting tool 218 for connecting the connecting member to the mating member cannot be inserted and fixed in the resin bent tube 202 unless the bending is performed. If these connectors 218 are inserted and fixed in advance in the straight tubular material tube 202A, the connectors 218 (which are usually made of resin) are deformed by the subsequent heating inside the heating furnace 216. Because it will wake up.

In other words, in the case of this manufacturing method, the connection fitting 218 cannot be inserted and fixed until the bent shape is given by heating in the heating furnace 216. In this case, the resin bent pipe is three-dimensionally formed. With a complicatedly curved shape, it becomes difficult to automate the operation of inserting and fixing the connecting tool 218 to the end of the bent resin pipe. This has also been a major factor that has hindered the automation of the manufacture of bent resin pipes.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems. Claim 1
The present invention relates to a method for manufacturing a bent resin tube, comprising: (a) a step of preparing a straight tubular material tube of a thermoplastic resin comprising at least one layer; and (b) moving the material tube in the longitudinal direction while moving the material tube in the longitudinal direction. (C) forcibly bending the processed portion along the outer peripheral portion of the bending roller disposed in front of the planned processed portion; and (c) the inner peripheral side and the outer peripheral side of the forcibly curved curved portion. Hot air is blown toward the curved portion from both directions to soften and plastically deform the curved portion, and bend the curved portion into a shape along the outer peripheral portion of the bending roller. Cooling the bent portion by blowing cold air to the formed bent portion.

According to a second aspect of the present invention, in the first aspect, a front portion of the processing portion of the material pipe is pressed against an outer peripheral portion of the bending roller, and the processing portion is rotated by the rotating motion of the bending roller. It is characterized in that it is pressed against the outer peripheral portion of the bending roller to forcibly bend.

According to a third aspect of the present invention, in the first or second aspect, the bending roller forms the bending groove having a depth such that at least half of the cross section of the bent portion of the material pipe is fitted into the bending groove. Along with the outer peripheral portion of the roller, for blowing the hot air to the bottom of the fitting groove,
It has a passage hole extending in the circumferential direction.

According to a fourth aspect of the present invention, in the third aspect, the bending roller is provided with a plurality of through holes in the side wall portion of the fitting groove, which penetrate in and out of the side wall portion at a circumferential interval. It is characterized by having.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a tubular connecting member for connecting at least one end of the resin bent tube to a tubular mating member is provided by the straight tubular material tube. The method is characterized in that a step of inserting and fixing in advance to the inner circumference of one end is provided next to the step of preparing the straight tubular material pipe.

According to a sixth aspect of the present invention, there is provided (a) a gripping device for gripping a straight tubular material tube of a thermoplastic resin, and (b) disposed in front of the gripping device, and the material tube is arranged along an outer peripheral portion. (C) a bending device provided with a bending roller for forcibly bending and bending the material tube; and (c) the holding device for supplying the material tube gripped by the gripping device to an outer peripheral portion of the bending roller. And (d) from the inner peripheral portion and the outer peripheral portion of the curved portion, at a distance from the curved portion to soften the curved portion, (E) a pair of hot air blowing devices for blowing hot air to the inner peripheral portion and the outer peripheral portion of the curved portion, which are disposed opposite to the inner peripheral side and the outer peripheral side of the curved portion; And a blowing device for blowing cool air.

[0018]

As described above, according to the production method of the present invention, a thermoplastic resin is preliminarily formed into a straight tube in advance.
This straight tubular material tube is moved in the longitudinal direction, and the processed portion is pressed against the outer peripheral portion of the bending roller disposed in front to forcibly bend, and in this state, the inner peripheral side and the outer peripheral side of the curved portion are bent. Hot air is blown from each direction to the curved part to soften and plastically deform it, and then it is cooled with cold air.In this manufacturing method, necessary parts are partially bent and formed, and Since a bent shape can be provided, there is no need for a whole constraining type for constraining the whole to a predetermined bent shape as in the prior art.Therefore, the whole is heated in a heating furnace, and then the whole is cooled. This eliminates the need for manual work to insert and set the material pipe into the overall constrained mold, and also removes the bent resin pipe after heating, making it easy to automate the production of bent pipes. it can. As a result, the productivity can be greatly increased, and the production cost of the bent resin pipe can be reduced.

Furthermore, since various shapes can be imparted by using the same bending roller, an extremely large number of exclusive whole constraining dies are prepared according to the type, shape, size, etc. of the resin bent tube as in the prior art. In addition, it is not necessary to perform such operations, and in addition, it is possible to easily realize high-mix low-volume production, and also facilitate mixed production.

Further, according to the present invention, after bending a specific portion to be processed, the raw material tube is forwardly fed or rotated around the axis together with the material tube, and the other portion to be processed is formed using the same bending roller. It is possible to easily form a bent resin tube having a complicated shape that is bent two-dimensionally or three-dimensionally.

The manufacturing method of the present invention also applies hot air to a portion where the material tube is forcibly bent along the outer peripheral portion of the bending roller from both the inner peripheral side and the outer peripheral side of the curved portion. It is characterized in that the curved portion is formed into a shape along the outer peripheral portion of the bending roller by spraying.

For example, it is conceivable to blow hot air to the curved portion only from one direction on the outer peripheral side. In this case, however, the curved portion is heated only from one direction, so that the entire curved portion can be uniformly heated. Can not be heated.
For this reason, there arises a problem that the curved portion, that is, the bent portion is kinked, or that the cross-sectional shape which should be originally a circular shape becomes a flat elliptical shape.

However, in the manufacturing method of the present invention, the curved portion is softened and plastically deformed by blowing hot air from both the inner peripheral side and the outer peripheral side to the curved portion.
The curved portion can be uniformly heated, and the bending can be favorably performed. That is, it is possible to obtain a stable resin bent pipe having a good bent shape and excellent quality. In the manufacturing method of the present invention, the cold air can be sprayed on the bent portion from both the inner and outer circumferential sides. By doing so, cooling can be performed uniformly and promptly.

Furthermore, when the front portion of the processed portion of the material tube is pressed against the outer peripheral portion of the bending roller to forcibly bend, the bending can be performed by rotating the bending roller.

Further, an outer peripheral portion of the bending roller is provided with a fitting groove having a depth for fitting at least half of a cross section of the material tube, more specifically, a bent section of the material tube, and a hot air is provided at the bottom of the fitting groove. A circumferentially extending through hole for spraying the air can be formed (claim 3). With this configuration, the hot air blown from the inner peripheral side can be efficiently blown through the bending roller to the inner peripheral surface side of the curved portion of the material pipe, and the bent portion can be formed more favorably. .

Here, the hot air passage hole at the bottom of the fitting groove may be formed in a slit shape along the circumferential direction. By forming the hot air passage hole at the bottom in such a slit shape, the hot air can be blown directly to the curved portion with high efficiency over a wider area.

In the present invention, the bending roller may be
It is possible to use a fitting groove having a plurality of through holes penetrating the fitting groove into and out of the side wall at circumferential intervals. By using such a bending roller,
Hot air can also act on the curved portion from the outside of the side wall portion, and the curved portion can be more uniformly and entirely heated, so that the bent portion can be formed more favorably. Here, the through hole in the side wall portion may be formed by forming small holes in a circumferential direction at a predetermined pitch.

In the present invention, the bending roller may be:
A cutout hole formed in the circumferential direction along the inner peripheral side of the fitting groove and penetrating the bending roller in the axial direction can be used. The axial cutout allows the blown hot air to flow around the curved portion more favorably, and the curved portion can be entirely heated by the hot air, so that the bent portion can be formed more favorably.

According to the manufacturing method of the present invention, a portion to be processed is partially bent by using a bending roller and by blowing hot air to obtain a resin bent pipe having a desired bent shape as a whole. In this case, there is no need to heat the entire material tube. Therefore, it is possible to insert and fix a connecting tool to at least one end of a straight tubular material pipe in advance, and to bend a desired processed portion in that state.

In the case where a straight tube is prepared and then a step of inserting and fixing a connector to the inner periphery of one end of the tube is performed in advance (claim 5), it is complicatedly bent as in the prior art. The connector can be inserted and fixed to the inner periphery of one end of the material pipe that extends linearly, instead of inserting and fixing the connector to a bent pipe having a bent shape. It can be easily realized. As a result, both the bending and the insertion and fixing of the connector can be automated, and the process up to the insertion and fixing of the connector can be greatly shortened and the efficiency can be increased as compared with the conventional case.

Claim 6 relates to a bending equipment.
According to the bending equipment, the above-described manufacturing method can be suitably performed.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 10 denotes a bent resin tube made of a thermoplastic resin, and reference numeral 11 denotes a connector inserted and fixed to each end of the bent resin tube 10. Here, the connection tool 11 is made of resin.

FIGS. 2 to 5 show a specific configuration of a bending equipment used for manufacturing the bent resin pipe 10. As shown in FIGS. In FIG. 2, reference numeral 13 denotes a slide member which moves forward and backward in the left-right direction in FIG. 2, and a chuck device (gripping device) 12 is provided at a distal end thereof.

The chuck device 12 is for gripping a straight tubular material tube 10A made of a thermoplastic resin, which will be described later. It is sent forward by advancing in the direction.

Reference numeral 14 denotes a screw, and the slide member 13 is screwed to the screw 14. When the screw 14 is rotationally driven by the driving device 18, the slide member 13 is moved under the guide of the guide rail 16. It is driven forward and backward in the left-right direction in FIG.

Here, the chuck device 12 is driven to rotate by a motor as a rotation driving device. That is, the straight tube 10A gripped by the chuck device 12 can be rotated.
Incidentally, reference numeral 20 denotes a cover, on which various mechanisms are disposed.

In FIG. 2, a bending roller 22 for bending and forming a portion to be processed of the material pipe 10A is rotatably disposed at the right end, and the bending roller 22 is opposed to each other with the bending roller 22 interposed therebetween. A first and a second pair of hot air blowing devices 24-1 and 24-2 are provided. still,
The bending roller 22 is rotationally driven via a chain 28 by a rotational driving device (not shown).

In FIG. 2, a first cold air blowing device 26-1 is located on the left side of one first hot air blowing device 24-1.
And the other second hot air blowing device 24
As shown in FIG. 3, the other second cold air blowing device 26-2 is provided at the lower position of -2.

The first and second pairs of hot air blowing devices 24
2 and 4 are normally at the positions indicated by solid lines in FIGS. 2 and 4, and when hot air is blown, each is rotated clockwise by 45 ° as indicated by the dotted lines in FIG. Hot air blowing is performed in that state.

At this time, the first cold air blowing device 26-
1 is also 45 ° together with the first hot air blowing device 24-1.
Rotating, and still another second cold air blowing device 26-2.
Are in the same rotational angle position and rise from the descending position, and in this state, cool air is blown.

The first and second hot air blowing devices 24-
Each of the nozzles 1 and 2-2 has a nozzle 30 at the tip end thereof, and jets hot air through these nozzles 30 with vigor. Similarly, the first and second pair of cold air blowing devices 26-1 and 26-2 also have nozzles 32 at their distal ends, and jet the cool air from these nozzles 32 vigorously.

The first cold air blowing device 26-1 is shown in FIG.
Is connected to a horizontal cylinder 36 via a bracket 34 as shown in detail in FIG.
With this, it can be moved back and forth in the left-right direction in the figure. On the other hand, as shown in FIG. 5, the second cold air blowing device 26-2
The cylinder 40 is moved up and down by the cylinder 40.

In FIG. 3, reference numeral 42 denotes a turning arm which makes a turning motion around the axis of the shaft 44 and in an angle range of 45 °. The revolving arm 42 revolves in conjunction with the rotation of the bending roller 22. Specifically, the bending roller 22 is adapted to rotate integrally with the shaft 46, and the shaft 46 and the shaft 4
4 are operatively connected via an intermediate shaft 48.

That is, the lower end of the shaft 46 is connected to the upper end of the intermediate shaft 48 and the pulley fixed to the lower end of the shaft 46 and the intermediate shaft 48 via the belt 50 wound therearound.
And the lower end of the intermediate shaft 48 is
A pulley fixed to the lower end and a pulley fixed to the upper end of the shaft 44 and a belt 52 wound around the pulley are connected to the shaft 44 on the turning arm 42 side. When the 46 is driven to rotate, the bending roller 22 makes a 90 ° rotational movement, and in conjunction therewith, the turning arm 42 makes a 45 ° turning movement.

Each end of the swing arm 42 has a support 54
And 56 are provided in an upright state. The first hot air blowing device 24-1 and the first cold air blowing device 26-1 are supported by the support arm 54 so as to rotate integrally with the turning arm 42. The other second hot air blowing device 24-2 and the second cold air blowing device 26-2
Is supported by the column 56 so as to rotate integrally with the turning arm 42.

As shown in FIG. 3, the first hot air blowing device 24-1 and the second hot air blowing device 24-2 are supported by levers 57 provided on columns 54 and 56, respectively. . These levers 57 also have struts 5
The vertical cylinders 58 attached to the first and second hot air blowing devices 24-1 are connected to each other by rotating the respective levers 57 by the expansion and contraction of the cylinders 58. , 24-2 can be rotated from the horizontal posture shown in FIG. 3 to an inclined state with the tip nozzle 30 facing upward as shown in FIG.

FIGS. 6 and 7 specifically show the structure of the bending roller 22. FIG. As shown in these figures, the bending roller 22 has a substantially fan-shaped planar shape. A boss 60 is provided at the center of the rotation, and the boss 60 is fitted in the fitting hole 62 of the boss 60 to the rotary drive shaft.

A flat plate portion 64 extends from the boss portion 60, and a fitting groove 66 for fitting the material pipe 10A is formed along the entire circumference along the outer peripheral portion.
Here, as shown in FIGS. 7 and 8, the fitting groove 66 is formed with a depth that fits at least half of the cross section of the material pipe 10A.

The fitting groove 66 is defined by a bottom 68 and a pair of side walls 70. The bottom portion 68 is formed with hot air and cold air passage holes 72 extending in the circumferential direction. Furthermore, a plurality of circular small holes 74 are formed in the pair of side wall portions 70 at intervals in the circumferential direction, and are formed over substantially the entire circumferential length. On the other hand, the flat plate portion 64 also has a circular arc-shaped notch hole 76 formed in the axial direction of the bending roller 22 so as to extend therethrough along the circumferential direction.

Next, a method for manufacturing the bent resin pipe of the present embodiment using the bending equipment having the above-mentioned structure will be specifically described below with reference to FIGS. 9 to 13 together with the operation of the bending equipment. As shown in FIG. 9, in the manufacturing method of this example, first, a thermoplastic resin is extruded in a linear shape, and then cut into predetermined dimensions.
A straight tube 10A is obtained. Then, as shown in FIG. 9 (II), a resin connector 11 is inserted and fixed to each end of the material tube 10A.

In this state, the raw material tube 10A is set in the bending equipment, and the vicinity of one end in the longitudinal direction is gripped by the chuck device 12 of the slide member 13 at the retracted position. Subsequently, the slide member 13 is moved forward in the right direction in FIG.
A is moved forward. FIG. 10 (III) shows the state at this time.

When the intended processed portion of the material pipe 10A reaches the position of the bending roller 22, a pair of pressers 7
8, 80 are forwardly moved downward in the figure as shown in FIG. 10 (IV). At this time, only one of the first pressers 78 presses the material pipe 10A against one end of the bending roller 22 in the circumferential direction. Specifically, the material pipe 10A is pressed against the bottom 68 of the fitting groove 66 of the bending roller 22.
The other second presser 80 contacts the material tube 10A, but at this point, the material tube 10A has not yet been pressed against the bending roller 22.

At this time, the first hot air blowing device 24-
Each of the first and second hot air blowing devices 24-2 is shown in FIG.
As shown in (IV), the material pipe 10A faces in a direction perpendicular to the feed direction. Further, the first cold air blowing device 26-1 is located on the left side of the first hot air blowing device 24-1 in the drawing, and the second cold air blowing device 26-2 is located in the second hot air blowing device 24-2. It is located below. Each of the hot air blowing devices 24-1 and 24-2 has a horizontal posture as shown in FIG.

Then, the bending roller 22 is moved from the state shown in FIG.
Rotate 90 ° to the state shown in (V). When the rotation is completed, the second presser 80 further moves forward,
With respect to the other end of the bending roller 22 in the circumferential direction, the material pipe 1
0A is pressed. That is, the processed portion of the material pipe 10A is forcibly pressed against the outer peripheral portion of the bending roller 22 by the rotational motion of the bending roller 22, specifically, the bending roller 22 inside the fitting groove 66, and is forcedly bent. Become.

When the bending roller 22 rotates 90 °, the first hot air blowing device 24-1 and the first cold air blowing device 26-1 and the second hot air blowing device 24-2 and the second cold air blowing device 24-2. The spray device 26-2 is rotated 45 degrees clockwise.

The hot air blowing device 24-
1, 24-2 and the cool air blowing devices 26-1, 26-2 are 4
After the rotation by 5 °, the hot air blowing devices 24-1 and 24-2 then apply a predetermined amount of hot air to the curved portion of the material pipe 10A from both the inner circumferential side and the outer circumferential side. It is sprayed over time (see FIG. 11 (VI)). As a result, the bending portion is softened by heating, and the bending roller 22 is softened.
Is plastically deformed into a curved shape corresponding to the outer peripheral shape of. That is, it is bent.

When the hot air is blown, the bending roller 2
As described above, since a slit-shaped hot air passage hole 72 is formed in the bottom portion 68 in the circumferential direction as described above, a plurality of small holes 74 are further formed in the pair of side wall portions 70 at intervals in the circumferential direction. Since it is formed, furthermore, since the arc-shaped cutout hole 76 is formed in the flat plate portion 64, the hot air blown from the pair of hot air blowing devices 24-1 and 24-2 sufficiently circulates around the curved portion. Thus, the curved portion is uniformly and uniformly heated by the hot air. Therefore, the curved portion is plastically deformed into a favorable shape, that is, bent.

The bending roller 22 has a fitting groove 66 formed deeply, and has a curved portion formed by a bottom portion 68 and a pair of side wall portions 7.
Since the shape is well constrained by 0, hot air is evenly blown to the curved portion to uniformly heat the curved portion. Therefore, no kink occurs during the bending, and the curved portion is flat. It is not formed into a shape, but is bent into a good cross-sectional shape (see FIG. 8).

When the hot air blowing has been completed, the first and second pair of hot air blowing devices 24-1 and 24-24 are successively provided.
2 is an upward inclined posture as shown in FIG. 5, that is, a retracted posture, and then a first and second pair of cold air blowing devices 26
-12 and 26-2 are arranged opposite to each other on the inner peripheral side and the outer peripheral side with a distance from the curved portion, that is, the bent portion, by the horizontal cylinder 36 and the vertical cylinder 40 (FIG. 12 ( Next, cool air is blown against the bent portion to cool the bent portion. In this example, the description has been given assuming that the hot air is blown after the bending roller 22 rotates by 90 °. However, the hot air may be blown at the same time as the rotation of the bending roller 22 starts.

The first after completion of hot air blowing and cold air blowing
And the second hot air blowing devices 24-1 and 24-2 and the first and second cold air blowing devices 26-1 and 26-2 retreat again to the initial position (see FIG. 12 (VIII)). The bending roller 22 and the pair of pressers 78 and 80 also perform a return movement,
Subsequently, the material tube 10A is moved forward as shown in FIGS.

Thereafter, as shown in FIGS. 13 (IX) and 13 (B), the material tube 10A is rotated about the axis by the rotation of the chuck device 12 as necessary, and in that state, the above-described procedure is repeated again. By bending the next part to be processed, the resin bent pipe 10 having a three-dimensionally bent shape can be obtained. In addition, it is of course possible to end the processing only by two-dimensional bending.

According to the manufacturing method of the present embodiment as described above, the required portion of the material pipe 10A can be partially bent and formed to give the entire bent shape, and the entire bent portion can be formed into the predetermined bent shape as in the conventional case. It is not necessary to provide an entire constraining type for confining the heat sink in a heating furnace, and to heat the whole in a heating furnace and then cool the whole. Furthermore, the work of inserting and setting the straight tubular material tube 10A into the entire constraining type by manual work and the work of removing the resin bent tube 10 after heating can be made unnecessary, and the production of the resin bent tube 10 can be easily automated. be able to. As a result, the productivity can be greatly increased, and the production cost of the bent resin pipe 10 can be reduced.

Further, since various shapes can be imparted using the same bending roller 22, a large number of exclusive whole constraining types according to the type, shape, dimensions, etc. of the resin bent tube 10 as in the prior art can be provided. There is no need to prepare them, and in addition, multi-product small-quantity production can be easily realized and mixed production can be facilitated.

Further, according to the present embodiment, after bending a specific portion to be processed, the material pipe 10A is advanced and rotated about the axis to bend another portion to be processed using the same bending roller 22. It is possible to mold the resin bent pipe 10 having a complicated shape bent three-dimensionally.

In the manufacturing method of the present embodiment, the curved portion is plastically deformed by blowing hot air to the curved portion from both the inner peripheral side and the outer peripheral side, so that the curved portion can be uniformly heated. Bending can be favorably performed. That is,
It is possible to obtain a stable resin bent pipe 10 having a good bent shape and excellent quality.

Further, the bending roller 22 has a material tube 10A.
Is provided with a fitting groove 66 having a depth to fit more than half of the cross section of the fitting groove 66, and a through hole 72 extending in the circumferential direction for blowing hot air to the bottom 68 of the fitting groove 66. The hot air blown from the side is bent by the bending roller 22.
Can be directly sprayed on the inner peripheral surface side of the curved portion of the material pipe 10A, and this can be efficiently heated and softened, so that the bent portion can be formed more favorably.

Further, in the side wall portion 70 of the fitting groove 66 of the bending roller 22, small holes 74 as through holes penetrating the inside and outside of the bending groove 22 are formed at intervals in the circumferential direction.
Since the cutout hole 76 is also formed on the inner peripheral side, hot air can be favorably applied to the curved portion, and the curved portion can be more uniformly heated by the hot air as a whole. The bent portion can be formed more favorably.

FIG. 14 shows the results of a confirmation test of the presence or absence and shape of hot air passage holes, through holes, and the like in the bottom portion 68 of the fitting groove 66 and the pair of side wall portions 70. As shown in the results, the hot air passage hole in the bottom portion 68 is formed in a slit shape, and further, a through hole is provided in the side wall portion 70, and the through hole is formed as a circular small hole, which is formed in the circumferential direction. It can be seen that particularly good results can be obtained in the case where a plurality are provided at a predetermined pitch.

In the manufacturing method of this embodiment, it is not necessary to heat the entire material tube 10A at the time of bending as described above. Therefore, it is possible to insert and fix the connecting tool 11 to both ends of the straight tubular material tube 10A in advance, and in this state, it is possible to bend a desired processed portion. Thereby, automation of insertion and fixation of the connection tool 11 can be easily realized. As a result, the process up to the insertion and fixation of the connection tool 11 can be significantly shortened and the efficiency can be increased as compared with the conventional case.

Although the embodiment of the present invention has been described in detail, this is merely an example, and the present invention can be configured and implemented in various modified forms and modes without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a bent resin pipe obtained by a manufacturing method of the present invention in a state where a connecting tool is inserted and fixed.

FIG. 2 is a diagram showing a plan configuration of a bending equipment according to an embodiment of the present invention.

FIG. 3 is a diagram showing a front configuration of the same bending equipment.

FIG. 4 is a diagram showing a planar configuration of a main part of the same bending equipment.

FIG. 5 is a diagram showing a front configuration of a main part of the same bending equipment.

FIG. 6 is a perspective view showing a configuration of a bending roller in the same bending equipment.

FIG. 7 is a plan view, a side view, and a partially cutaway side view showing the configuration of the same bending roller.

FIG. 8 is an essential part cross-sectional view showing a fitting groove of the same bending roller and a peripheral portion thereof.

FIG. 9 is a view showing one step of a method of manufacturing a bent resin pipe according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram of a step following FIG. 9;

FIG. 11 is an explanatory view of a step following FIG. 10;

FIG. 12 is an explanatory diagram of a step following FIG. 11;

FIG. 13 is an explanatory diagram of a step following FIG. 12;

FIG. 14 is a diagram illustrating a result of a confirmation test of an effect of the bending roller illustrated in FIGS. 6 and 7.

FIG. 15 is an explanatory diagram illustrating an example of an application of a bent resin pipe.

FIG. 16 is a view showing main steps of a conventional method for manufacturing a bent resin pipe.

FIG. 17 is an explanatory diagram of a step following FIG. 16;

FIG. 18 is an explanatory diagram of a defect in a conventional manufacturing method.

[Description of Signs] 10 Resin bent pipe 10A Material pipe 11 Connector 12 Chuck device (gripping device) 13 Slide member 22 Bending roller 24-1, 24-2 Hot air blowing device 26-1, 26-2 Cold air blowing device 66 Fitting Groove 68 Bottom 70 Side wall 72 Through hole 74 Small hole (through hole)

Continuing from the front page (72) Inventor: Kawazu Tsugio, Higashi 3-chome, Komaki City, Aichi Prefecture Tokai Rubber Industries Co., Ltd. 72) Inventor Shigeo Koma 1-3-1 Higashi 3-chome, Komaki City, Aichi Prefecture F-term (reference) 4F209 AG12 AH17 AK01 AK02 NA01 NB02 NG03 NJ15 NK07 NK10 NW15

Claims (6)

[Claims] (A) a step of preparing a straight tubular material pipe of a thermoplastic resin comprising at least one layer; and (b) moving the material pipe in the longitudinal direction, and in front of a predetermined processed portion of the material pipe. (C) forcibly bending the workpiece along the outer peripheral portion of the bending roller disposed in the bending roller; and (c) forming the curved portion from both the inner peripheral side and the outer peripheral side of the forcibly curved curved portion. Hot air is blown toward the bending section to soften and plastically deform the curved portion, and bend the curved portion into a shape along the outer peripheral portion of the bending roller; and (d) apply cold air to the bent and formed bent portion. Cooling the bent portion by spraying. 2. The material pipe according to claim 1, wherein a front portion of the processing portion of the material tube is pressed against an outer peripheral portion of the bending roller, and the processing portion is rotated by the rotating motion of the bending roller. A method for manufacturing a bent resin pipe, comprising forcibly bending the bent pipe. 3. The bending roller according to claim 1, wherein the bending roller has a fitting groove having a depth for fitting at least half of a cross section of the bent portion of the material pipe in an outer peripheral portion of the bending roller. A method for manufacturing a bent resin pipe, comprising: a passage hole extending in a circumferential direction for blowing the hot air at a bottom of the fitting groove. 4. The method according to claim 3, wherein the bending roller comprises:
A method for manufacturing a bent resin pipe, comprising: a plurality of through-holes penetrating the side wall portion of the fitting groove into and out of the side wall portion at intervals in a circumferential direction. 5. A tubular connector for connecting at least one end of the bent resin pipe to a tubular counterpart member according to any one of claims 1 to 4, at an inner periphery of one end of the straight tubular material pipe. A method for manufacturing a bent resin tube, comprising a step of inserting and fixing in advance after the step of preparing the straight tubular material pipe. 6. A (a) gripping device for gripping a straight tube of thermoplastic resin, and (b) a gripping device disposed in front of the gripping device.
A bending device provided with a bending roller for forcibly bending and forming the material tube along the outer peripheral portion; and (c) the bending device for supplying the material tube gripped by the gripping device to the outer peripheral portion of the bending roller. A feed device for moving the gripping device in the longitudinal direction of the material tube to feed the material tube forward; and (d) the bending portion for softening the bending portion from the inner and outer peripheral portions of the bending portion. A pair of hot-air blowing devices for blowing hot air to the inner peripheral portion and the outer peripheral portion of the curved portion, which are opposed to the inner peripheral side and the outer peripheral side of the curved portion at a distance from each other; A cold air blowing device for blowing cold air to the part after hot air is blown.